R1-2600159
discussion
UL-WUS and Operation
From Huawei
Summary
This document from Huawei analyzes the necessity and benefits of Uplink Wake-Up Signaling (UL-WUS) for 6G, presenting 6 key proposals and 12 observations across motivation, performance evaluation, and design aspects to enable demand-driven BS wake-up for network energy savings.
Position
Huawei proposes studying UL-WUS as a mechanism to transform BS operation from periodic 'always on' activity to demand-driven wake-up, enabling dynamic sleep and long BS sleep durations without UE performance penalties. They propose extending the Rel-19 on-demand SSB concept from carrier aggregation to single cell/carrier scenarios, where a connected UE requests additional synchronization signals (AD-SS) via UL-WUS. They present a technical case that UE-triggered AD-SS provides better NES gains than NW-triggered always-on SS, and that handling AD-SS and UL-WUS in BS low-power (LP) mode yields further considerable energy savings compared to handling by the main radio (MR). They propose studying high-capacity UL-WUS design to carry UE-dedicated information and support multiple use cases including on-demand UL data transmission, OD-SIB1 in standalone deployment, and a 'No UL Data' indication to assist the network in distinguishing PUSCH skipping from PDCCH missing.
Key proposals
- Proposal 1 (Sec 2.1): Study UL-WUS and the corresponding procedure for requesting additional synchronization signal by the UE in connected state.
- Proposal 2 (Sec 2.2): Study UL-WUS and the corresponding procedure for requesting OD-SIB1 in standalone deployment.
- Proposal 3 (Sec 2.3): Study UL-WUS and the corresponding procedure for requesting on-demand UL data transmission for UE in connected state.
- Proposal 4 (Sec 4.1): Study UL-WUS design with high capacity to enable applications requiring WUS to carry UE dedicated information as well as applications for various scenarios considering UE energy consumption.
- Proposal 5 (Sec 4.1): Identify the coverage requirements of UL-WUS considering different use cases.
- Proposal 6 (Sec 4.2): Study other potential functionalities enabled by UL-WUS and their corresponding procedures including sending indications from UE to BS (e.g., a 'No UL data' indication) for alignment between UE and BS.